A psychiatrist rushed the assessment of patients for sex change surgery and did not follow proper procedures, a medical tribunal has heard.
Dr Russell Reid is being made subject to a GMC hearing
Dr Russell Reid, 63, of west London, a former NHS doctor, faces charges relating to five patients at a hearing of the General Medical Council.
Richard Tyson, acting for the GMC, told the hearing Dr Reid had "jeopardised the safety of his patients".
Dr Reid, who worked in private practice in London, denies all the charges.
The GMC fitness to practice panel heard that Dr Reid, a leading authority on gender identity disorder, worked at the gender identity clinic of Charing Cross Hospital in west London from 1982 to 1990.
In 1990 he established a private practice in Earls Court, specialising in transsexualism.
Mr Tyson said the complainants in this case were four psychiatrists who work at the Charing Cross Hospital gender identity clinics.
He said the fifth complainant was one of his patients, identified only as patient F.
Mr Tyson said that Dr Reid "consistently jeopardised the safety of his patients, and in particular by prescribing to them irreversible hormones to help change their gender without appropriate assessments and physical checks."
The charges cover a period from 1988 to 2003.
Mr Tyson also told the panel the Charing Cross Hospital gender identity clinic was the oldest and largest in the world, handling 500 cases a year.
The clinic, he said, deals with about 90% of all NHS work in this area of medicine.
Dr Reid has denied inappropriate behaviour towards the patients and he has also denied acting contrary to guidance given in the Harry Benjamin International Gender Dysphoria Association standards of care.
He has further denied a charge of serious professional misconduct in relation to the patients.
The hearing continues.